Booleans and comparisons · ⁨ブール値と比較⁩

True and false

• A boolean is one of just two values: true or false.
• Compare values to get a boolean: === (equal), !== (not equal), < > <= >=.

console.log(5 === 5);   // → true
console.log(3 > 7);     // → false

Combine tests

• && means and — true only when both sides are true.
• || means or — true when at least one side is true.
• ! means not — it flips true and false.

console.log(true && false);   // → false
console.log(!true);           // → false

Watch out

• Always compare with ===, not ==. The older == quietly converts types: 0 == "" is true!
• === checks value and type, which is what you almost always want.

Common mistakes

• Prefer === (strict) over ==, which does surprising type coercion.
• && is AND, || is OR, ! is NOT.

Now you try

• Each task logs true or false.
• Press Check answer to test it.